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Hyperspace2
Oct12-10, 11:54 AM
What are the practical uses of op amp subtractor, integrator, differentiator, inverter?

One I know that of op amp adder is that they can be used as audio mixer .

berkeman
Oct12-10, 12:02 PM
What are the practical uses of op amp subtractor, integrator, differentiator, inverter?

One I know that of op amp adder is that they can be used as audio mixer .

Good thought on the adder/mixer. What would be some uses that you can think of for the other opamp building blocks that you mention?

Averagesupernova
Oct12-10, 12:34 PM
Technically a comparator is a type of subtractor. Consider it a subtractor with a very very very very very very very large gain. Not too hard to think of uses for a comparator.

schip666!
Oct12-10, 12:41 PM
Integrator == low pass filter
Differentiator == high pass filter
Inverter == Tea Party Filter... just kidding, sorry...

berkeman
Oct12-10, 12:57 PM
Inverter == Tea Party Filter... just kidding, sorry...

:rofl:

Hyperspace2
Oct12-10, 07:39 PM
Technically a comparator is a type of subtractor. Consider it a subtractor with a very very very very very very very large gain. Not too hard to think of uses for a comparator.
Ok I got it.
Integrator == low pass filter
Differentiator == high pass filter
Inverter == Tea Party Filter... just kidding, sorry...
Yeah, I also came to learn about the low pass filter and high pass filter too. But I think of them now as a independent circuit elements . Aren't they just combination of Resisitor and capacitors? I don't think they need op amp. Active High pass filter are just the combination of filter and op amp for High pass filter and amplification respectively. Similar in the case of the active low pass filter. Amn't I correct?

Averagesupernova
Oct12-10, 08:04 PM
An active filter has advantages over a passive. Have you done the math and made some comparisons?

waht
Oct12-10, 08:33 PM
Something I've recently worked with using an integrator. Perhaps might be of help.

The goal is to measure phase between two square waves. If you feed the two signals into a XOR gate, then one can show that the output will have different width or delta t which is directly proportional to a phase between the square waves.

The output looks something like this:

http://www.pcsilencioso.com/cpemma/graphics/swave.gif


The wider the signal, the more phase difference there is. Now, what you want to do is to get DC voltage output that is proportional to the phase difference, and all you have is this rectangular pulse wave. How would you recover the width?

The answer is with an integrator. We known that the amplitude is constant. If you integrate this rectangular pulse wave, then you get the area under the rectangle which is (Amplitude * Delta t) and the delta t is the width you are after which is proportional to phase difference.

Hyperspace2
Oct12-10, 08:45 PM
An active filter has advantages over a passive. Have you done the math and made some comparisons?
No I haven't tried it yet. I would like to look at it now.
Something I've recently worked with using an integrator. Perhaps might be of help.

The goal is to measure phase between two square waves. If you feed the two signals into a XOR gate, then one can show that the output will have different width or delta t which is directly proportional to a phase between the square waves.

The output looks something like this:

http://www.pcsilencioso.com/cpemma/graphics/swave.gif


The wider the signal, the more phase difference there is. Now, what you want to do is to get DC voltage output that is proportional to the phase difference, and all you have is this rectangular pulse wave. How would you recover the width?

The answer is with an integrator. We known that the amplitude is constant. If you integrate this rectangular pulse wave, then you get the area under the rectangle which is (Amplitude * Delta t) and the delta t is the width you are after which is proportional to phase difference.

Thanks for sharing . I am the begineer . I have to go long way ahead to view yours. I think you have many things for sharing.